import argparse

parser = argparse.ArgumentParser()
parser.add_argument("ifile", type=argparse.FileType('r'))

args = parser.parse_args()
lines = [line.strip() for line in args.ifile.readlines()]

hpos = 0
depth = 0
aim = 0

for line in lines:
    stuff = line.split(' ')
    command = stuff[0]
    parameter = int(stuff[1])

    if command == "forward":
        hpos += parameter
        depth += parameter * aim
    elif command == "down":
        aim += parameter
    elif command == "up":
        aim -= parameter

print(hpos * depth)